1. Field of the Invention
The present invention relates to an electronic device containing a circuit board mounted with an integrated circuit element such as a CPU or an LSI requiring measures against heat generation in a single case.
2. Related Background Art
In recent years, there is a trend toward a heavy use of an element provided with numerous semiconductors or a semiconductor integrated circuit element such as a CPU or an LSI having a microelectronic circuit whose internal wires are connected as a single solid in a special method. The integrated circuit element having the microelectronic circuit generates a large amount of heat in a process of operation. A temperature rise of the integrated circuit element may cause a defect such that the operation of the integrated circuit element becomes unstable. A further temperature rise may destroy the semiconductor. Therefore, conventionally a heat sink has been mounted on the integrated circuit element for a heat exchange between the heat sink and an air to cool the integrated circuit element by releasing heat of the integrated circuit element to the air, thereby preventing the integrated circuit element such as a CPU or an LSI from getting unstable in its operation due to the high temperature or from being destroyed by heat.
On the other hand, a server is provided with numerous electronic devices using the integrated circuit element as set forth in the above for use in a data communication network with communication lines or a computer network (LAN) for a high-speed data transfer with privately owned lines within a limited range such as a building or a premise. In other words, a significant temperature rise occurs due to the operation of numerous integrated circuit elements in a server of the kind described above. Therefore, conventionally there has been applied a method of cooling an entire room where the server is installed with a cooling unit and taking the cold air into the electronic devices to cool the integrated circuit elements.
In the conventional method, however, in which the cold air is taken with a propeller fan (air blower) provided at the rear of the electronic device and the cold air generated within the electronic device is blown against the integrated circuit element, the cold air is applied to only a part of the integrated circuit element inefficiently in cooling.
Therefore, a part of the cold air taken into a case with the air blower has been ejected to an outside of the electronic device without cooling the integrated circuit element.